This is a study of the language/thought disorder of schizophrenia, based on previous research which indicates that a linguistic description of the production of spontaneous speech by persons with the diagnosis of schizophrenia will yield valuable data concerning the nature of the communication disorder of schizophrenia a-nd may serve as a clinical marker unique to schizophrenia. Such understanding will assist in further explorations of the neuropsychological characteristics of schizophrenia as well as aide in the formulation of innovative treatment approaches. This project has the following goals: 1) to further' test hypotheses that the linguistic deviance noted in schizophrenic speakers is different in incidence and quality from the language production of other psychopathological states (in this instance, major depression) and from non-psychiatric controls; 2) to gain a greater understanding of the neuropsychological salience of findings of linguistic deviance by correlating the LDS with established measures of neuropsychological functioning; and 3) to develop the Hoffman/Sledge Linguistic Deviance Scale (LDS) as a practical and accessible, as well as a reliable, valid measure of an aspect of the functioning of people with schizophrenia. The study will utilize five subject groups as follows: two groups of schizophrenic patients-one impatient and one outpatient; two groups of affective disorder (major depression with mood congruent delusions) patients - one inpatient and one outpatient; and a group of non-psychiatric volunteers. The schizophrenic impatient group, the depressed groups, as well as the non-psychiatric volunteers, will be chosen to be comparable on age and gender with the outpatient schizophrenic group who will be chosen randomly from an already identified group of subjects from another research endeavor. There will be 25 subjects in each group for a total N of 125. Each subject will be administered the LDS and a variety of standardized clinical and neuropsychological tests. Each LDS protocol will be rated twice by trained college student raters (N=4) in order to adequately determine the reliability of the LDS. The results of these tests will be analyzed to test the differences among the comparison groups as well as to determine the correlation between the LDS and other measures.